In which annual session of Congress, the demand for 'Purna Swaraj' or complete independence was made?

1929 Lahore Session.

The correct answer is Option 2 - 1929 Lahore Session.

In the end of December 1929, the Congress held its annual session in the city of Lahore. The meeting was significant for two things: the election of Jawaharlal Nehru as President, signifying the passing of the baton of leadership to the younger generation; and the proclamation of commitment to “Purna Swaraj”, or complete independence. Now the pace of politics picked up once more. On 26 January 1930, “Independence Day” was observed, with the national flag being hoisted in different venues, and patriotic songs being sung. Gandhiji himself issued precise instructions as to how the day should be observed. “It would be good,” he said, “if the declaration [of Independence] is made by whole villages, whole cities even ... It would be well if all the meetings were held at the identical minute in all the places.”